"At least wars are about something!" says one bemused onlooker in the course of this shrewd documentary about the bareknuckle boxing scene in the Traveller community in Ireland and England – a dogfight cult for human beings, fuelled by feuds. For more than a decade, film-maker Ian Palmer has followed the long-running grudge between the Joyce and Quinn families, a grudge that had its ostensible origin in a 1992 brawl outside a London pub between two different Traveller clan members, which ended in the death of one and a manslaughter conviction for the other. But is that really what it's about? Or do they just love scrapping? The families are always making provocative videos challenging each other to a fight; then two unfit-looking, tubby guys emerge and square up: their training does not, clearly, include work on their abs. They beat the bejeepers out of each other in a secluded country lane surrounded by guys, most of whom have video cameras. (One of them is Palmer himself.) The combatants wind up covered in blood, but – crucially – there seems to be no permanent harm done. The resulting videos are shown in the back of vans; copies are sold in pubs, fuelling the queasy macho mythology. The loser returns to his camp site and nurses resentment and a desire for vengeance: another challenge is recorded and so it goes on. A black comedy without the comedy.